1. Field of the Invention
The present invention relates to a catalyst that is suitable for the preparation of an olefin polymer, which catalyst comprises a transition metal component and an organometal component. In a preferred embodiment, the present invention is related to a catalyst that is suitable for the preparation of a polymer, based on .alpha.-olefin. In a more preferred embodiment, the present invention relates to a catalyst that is suitable for the preparation of an amorphous copolymer of ethylene, an .alpha.-olefine and optionally a diene, which catalyst comprises a vanadium component and an aluminum component.
2. Background Information
Catalysts containing a vanadium component and an aluminum component are known in the art. They are used to obtain crystalline as well as amorphous olefin-polymers. Such catalysts are used to prepare the aforementioned amorphous copolymers, via a so-called Ziegler-Natta polymerization process. This process leads to the formation of both amorphous ethylene/.alpha.-olefine copolymers (also known as EAM rubbers) and amorphous ethylene/.alpha.-olefine/diene terpolymers (also known as EADM rubbers). As .alpha.-olefine, use is often made of propylene, which leads to the formation of EP or EPDM rubbers. An example of such a catalyst and such a process is found in U.S. Pat, No. 4,435,552, which teaches that the most suitable catalyst for such a polymerization consists of a vanadium component and an alkyl aluminum halide.
These known catalysts, however, have several drawbacks. One drawback of such catalysts is that their activity is poor and large amounts of organometal component are required to be used.
In the present invention, a new catalyst has been found, which leads to a different type of catalytic behavior from known catalysts. A catalyst of the present invention when used under process conditions analogous to known catalysts, yields a very different polymer from what known catalysts would yield, due to the unique composition of the catalyst.